Electrical energy storage (EES) installation in Korea covers installing batteries, the power conversion system (PCS) and related equipment so that electricity can be stored and supplied reliably. EES — more often called ESS (energy storage system) — stores energy and releases it when needed, for frequency regulation, peak shaving, smoothing renewable output, or replacing UPS and standby generators. Because these are large battery systems, every detail of polarity, earthing, ventilation and protection bears directly on safety. This guide covers two stages: PCS installation and battery installation.
Contents
- Common Pre-Work Review
- 1. Power Conversion System (PCS)
- 2. Battery Installation
- EES Components and Installation Points
- FAQ
- Reference Standards
- Summary
Common Pre-Work Review
Review the KEC, Korea’s Act on the Promotion of New and Renewable Energy, the national construction design code (KDS 31 00 00), the method statement and safety plan, design and fabrication drawings and the construction checklist. Prepare a multimeter, insulation tester, phase angle meter, level, hydrometer and thermometer, plus a mobile crane. Workers wear insulated helmets, flame-resistant clothing and insulated boots, and the area is marked off with barrier rope and signs.
1. Power Conversion System (PCS)
- Review operating modes based on battery capacity, PCS rating and equipment specifications.
- Confirm whether the system is grid-connected or for emergency use, and review control circuits and protection accordingly.
- For permanent grid connection, earth the enclosure and control cabinet and install earthing for the primary transformer as designed.
- Install cables to the EES with ancillary equipment, and connect auxiliary switches, supply and control cables.
- Prepare termination lists for power, control and interlock circuits from approved drawings, and install the dedicated switch, transfer switch and control cabinet.
The PCS converts incoming power to DC or AC and controls bidirectional power flow between storage and the grid.
2. Battery Installation
- Review battery type, rated capacity, energy capacity and DC short-circuit rating from the design and drawings.
- For cubicles, keep clearances and provide enough working space and lighting for maintenance.
- For racks, protect against corrosive gases or liquids and install in a clean, dry place out of direct sunlight that can hold the specified temperature.
- Check for visible defects and components such as connectors and caps, and install level where there is no risk of flooding.
- Ventilate lead-acid battery rooms to keep gas concentration within limits, and put cells with built-in hydrometers and thermometers at the end of the rack.
- Install a BMS with measurement (voltage, current, temperature), calculation (state of charge, life) and control (cell balancing, overcharge and over-discharge).
- Install earthing for battery racks and metal enclosures.
- Check polarity between batteries and at connections to charging equipment.
EES Components and Installation Points
| Component | Role | Installation point |
|---|---|---|
| Battery | Stores energy | Type, capacity and DC fault rating; polarity; no flooding or direct sun |
| PCS | AC/DC conversion, bidirectional control | Operating modes; enclosure earthing; interlock termination list |
| BMS | Measures, calculates, diagnoses and controls battery state | Confirm measurement, calculation and control functions |
| Protection and switching | Grid-connected or emergency protection | Dedicated switch, transfer switch, protection review |
| Battery room | Installation environment | Ventilation, temperature, working space and lighting |
Detailed clearances and ventilation rules follow the KEC, manufacturer guidance and client standards.
FAQ
Are EES and ESS the same thing?
Yes. The NCS uses Electrical Energy Storage (EES), while the industry more commonly says Energy Storage System (ESS).
What does a BMS do?
It measures battery voltage, current and temperature, calculates state of charge and life, and controls cell balancing, overcharge and over-discharge to keep the battery safe.
How do grid-connected and emergency systems differ?
They differ in operating mode and required protection. Permanently grid-connected systems need extra measures such as enclosure and primary transformer earthing.
Reference Standards
- Electricity Business Act (전기사업법) — law.go.kr
- Electrical Safety Management Act (전기안전관리법) — law.go.kr
- Electric Technology Management Act (전력기술관리법) — law.go.kr
- Electrical Construction Business Act (전기공사업법) — law.go.kr
- Occupational Safety and Health Act (산업안전보건법) — law.go.kr
- Korea Electro-technical Code (KEC, 한국전기설비규정) — law.go.kr
- Technical Standards for Electrical Equipment (전기설비기술기준) — law.go.kr
- KEPCO design standards and substation construction practice; Korean Industrial Standards (KS)
- NCS competency unit Electrical Energy Storage (EES) Installation (EES설비 공사, 1901070318_22v2; NCS is Korea’s National Competency Standards) — ncs.go.kr
Summary
The most common mistakes are connecting batteries without checking polarity and putting off battery room ventilation and temperature conditions. The PCS depends on operating mode and grid protection and earthing; batteries on capacity review, environment, the BMS and polarity checks. Related guides: Substation Auxiliary Power Installation, HVDC Converter Station Construction, Digital Substation System Installation. A Korean version of this guide is available here.
This article restructures the Korean NCS competency unit ‘Electrical Energy Storage (EES) Installation’ (EES설비 공사, code 1901070318_22v2) as a practical reference. Actual work must follow applicable standards and the judgment of qualified professionals; always confirm specific values, deadlines and criteria against the latest regulations and client standards.
Written/reviewed by VOLT · Last updated 2026-10-26